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1.
ScientificWorldJournal ; 2024: 8128813, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38827814

RESUMO

The genus Hypericum comprises a large number of species. The flower, leaf, stem, and root of the Hypericum species are widely used in traditional medicine in different cultures. Many Hypericum species have been well investigated phytochemically and pharmacologically. However, only a few reports are available on the H. cordifolium native to Nepal. The present study aims to evaluate the phytochemical composition of different extracts, qualitative analysis of methanol extract of the flower and leaf using thin-layer chromatography (TLC), and the antioxidant properties of components by the TLC-DPPH. assay. The phenolic and flavonoid contents were estimated in different extracts of the leaf and stem, and their antioxidant and antibacterial activities were evaluated. In the phytochemical screening, phenolics and flavonoids were present in ethyl acetate, methanol, and 50% aq methanol extracts of both the leaf and stem. In TLC analysis, the methanol extract of flowers showed the presence of 11 compounds and the leaf extract showed the presence of 8 compounds. Both extracts contained chlorogenic acid and mangiferin. Hyperoside and quercetin were present only in the flower extract. In the TLC-DPPH. assay, almost all of the flower extracts and 5 compounds of the leaf extract showed radical scavenging potential. Estimation of phenolics and flavonoids showed that all the leaf extracts showed higher amounts of phenolics and flavonoids than stem extracts. Among leaf extracts, greater amounts of phenolics were detected in 50% aqueous methanol extract (261.25 ± 1.66 GAE/g extract) and greater amounts of flavonoids were detected in methanol extract (232.60 ± 10.52 CE/g extract). Among stem extracts, greater amounts of flavonoids were detected in the methanol extract (155.12 ± 4.30 CE/g extract). In the DPPH radical scavenging assay, the methanol extract of the leaf showed IC50 60.85 ± 2.67 µg/ml and 50% aq. methanol extract of the leaf showed IC50 63.09 ± 2.98 µg/ml. The methanol extract of the stem showed IC50 89.39 ± 3.23 µg/ml, whereas ethyl acetate and 50% aq. methanol extract showed IC50 > 100 µg/ml. In the antibacterial assay, the methanol extract of the leaf showed the inhibition zone of 12-13 mm and the stem extract showed the inhibition zone of 7-11 mm against S. aureus, E. coli, and S. sonnei, whereas both extracts were inactive against S. typhi. The findings of this study support the traditional use of this plant in Nepal for the treatment of diseases associated with bacterial infections. The present study revealed that the underutilized anatomical parts of H. cordifolium could be the source of various bioactive phytochemicals like other Hypericum species.


Assuntos
Antibacterianos , Antioxidantes , Flavonoides , Hypericum , Compostos Fitoquímicos , Extratos Vegetais , Hypericum/química , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/análise , Antioxidantes/farmacologia , Antioxidantes/química , Antioxidantes/análise , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Compostos Fitoquímicos/química , Compostos Fitoquímicos/análise , Compostos Fitoquímicos/farmacologia , Flavonoides/análise , Flavonoides/química , Folhas de Planta/química , Fenóis/análise , Fenóis/química , Testes de Sensibilidade Microbiana , Cromatografia em Camada Fina , Caules de Planta/química
2.
Curr Microbiol ; 81(7): 206, 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38831051

RESUMO

The presence of extended-spectrum beta-lactamase (ESBL)-producing Klebsiella pneumoniae in fresh fruits and vegetables is a growing public health concern. The primary objective of this study was to investigate the relationship between biofilm formation and extended-spectrum ß-lactamase (ESBL) production in K. pneumoniae strains obtained from fresh fruits and vegetables. Out of 120 samples analysed, 94 samples (78%) were found to be positive for K. pneumoniae. Among the K. pneumoniae strains isolated, 74.5% were from vegetables, whereas the remaining (25.5%) were from fresh fruits. K. pneumoniae isolates were resistant to at least three different classes of antibiotics, with ceftazidime (90%) and cefotaxime (70%) showing the highest resistance rates. While the high occurrence of ESBL-producing and biofilm-forming K. pneumoniae strains were detected in vegetables (73.5% and 73.7%, respectively), considerable amounts of the same were also found in fresh fruits (26.5% and 26.3%, respectively). The results further showed a statistically significant (P < 0.001) association between biofilm formation and ESBL production in K. pneumoniae strains isolated from fresh fruits and vegetables. Furthermore, the majority (81%) of the ESBL-producing strains harbored the blaCTX-M gene, while a smaller proportion of strains carried the blaTEM gene (30%), blaSHV gene (11%) or blaOXA (8%). This study highlights the potential public health threat posed by K. pneumoniae in fresh fruits and vegetables and emphasizes the need for strict surveillance and control measures.


Assuntos
Antibacterianos , Biofilmes , Frutas , Klebsiella pneumoniae , Testes de Sensibilidade Microbiana , Verduras , beta-Lactamases , Biofilmes/crescimento & desenvolvimento , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/isolamento & purificação , Verduras/microbiologia , beta-Lactamases/genética , beta-Lactamases/metabolismo , Frutas/microbiologia , Antibacterianos/farmacologia
3.
Curr Microbiol ; 81(7): 205, 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38831167

RESUMO

Bacteria can form aggregates in synovial fluid that are resistant to antibiotics, but the ability to form aggregates in cerebral spinal fluid (CSF) is poorly defined. Consequently, the aims of this study were to assess the propensity of four bacterial species to form aggregates in CSF under various conditions. To achieve these aims, bacteria were added to CSF in microwell plates and small flasks at static and different dynamic conditions with the aid of an incubating shaker. The aggregates that formed were assessed for antibiotic resistance and the ability of tissue plasminogen activator (TPA) to disrupt these aggregates and reduce the number of bacteria present when used with antibiotics. The results of this study show that under dynamic conditions all four bacteria species formed aggregates that were resistant to high concentrations of antibiotics. Yet with static conditions, no bacteria formed aggregates and when the CSF volume was increased, only Staphylococcus aureus formed aggregates. Interestingly, the aggregates that formed were easily dispersed by TPA and significant (p < 0.005) decreases in colony-forming units were seen when a combination of TPA and antibiotics were compared to antibiotics alone. These findings have clinical significance in that they show bacterial aggregation does not habitually occur in central nervous system infections, but rather occurs under specific conditions. Furthermore, the use of TPA combined with antibiotics may be advantageous in recalcitrant central nervous system infections and this provides a pathophysiological explanation for an unusual finding in the CLEAR III clinical trial.


Assuntos
Antibacterianos , Líquido Cefalorraquidiano , Humanos , Antibacterianos/farmacologia , Líquido Cefalorraquidiano/microbiologia , Bactérias/classificação , Bactérias/genética , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/fisiologia , Ativador de Plasminogênio Tecidual , Farmacorresistência Bacteriana , Testes de Sensibilidade Microbiana
4.
World J Microbiol Biotechnol ; 40(7): 231, 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38833075

RESUMO

To investigate the mechanism of Triton X-100 (TX-100) reducing the Ag+-resistance of Enterococcus faecalis (E. faecalis), and evaluate the antibacterial effect of TX-100 + Ag+ against the induced Ag+-resistant E. faecalis (AREf). The minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) of AgNO3 against E. faecalis with/without TX-100 were determined to verify the enhanced antibacterial activity. Transmission electron microscopy (TEM) was used to observe the morphological changes of E. faecalis after treatment. The intra- and extracellular concentration of Ag+ in treated E. faecalis was evaluated using inductively coupled plasma mass spectrometer (ICP-MS). The changes in cell membrane potential and integrity of treated E. faecalis were also observed using the flow cytometer. Moreover, AREf was induced through continuous exposure to sub-MIC of Ag+ and the antibacterial effect of TX-100 + Ag+ on AREf was further evaluated. The addition of 0.04% TX-100 showed maximal enhanced antibacterial effect of Ag+ against E. faecalis. The TEM and ICP-MS results demonstrated that TX-100 could facilitate Ag+ to enter E. faecalis through changing the membrane structure and integrity. Flow cytometry further showed the effect of TX-100 on membrane potential and permeability of E. faecalis. In addition, the enhanced antibacterial effect of TX-100 + Ag+ was also confirmed on induced AREf. TX-100 can facilitate Ag+ to enter E. faecalis through disrupting the membrane structure and changing the membrane potential and permeability, thus reducing the Ag+-resistance of E. faecalis and enhancing the antibacterial effect against either normal E. faecalis or induced AREf.


Assuntos
Antibacterianos , Farmacorresistência Bacteriana , Enterococcus faecalis , Testes de Sensibilidade Microbiana , Octoxinol , Prata , Enterococcus faecalis/efeitos dos fármacos , Enterococcus faecalis/crescimento & desenvolvimento , Octoxinol/farmacologia , Antibacterianos/farmacologia , Prata/farmacologia , Membrana Celular/efeitos dos fármacos , Potenciais da Membrana/efeitos dos fármacos , Microscopia Eletrônica de Transmissão , Nitrato de Prata/farmacologia
5.
J Water Health ; 22(5): 825-834, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38822462

RESUMO

Hospital wastewater has been identified as a hotspot for the emergence and transmission of multidrug-resistant (MDR) pathogens that present a serious threat to public health. Therefore, we investigated the current status of antibiotic resistance as well as the phenotypic and genotypic basis of biofilm formation in Pseudomonas aeruginosa from hospital wastewater in Dhaka, Bangladesh. The disc diffusion method and the crystal violet assay were performed to characterize antimicrobial resistance and biofilm formation, respectively. Biofilm and integron-associated genes were amplified by the polymerase chain reaction. Isolates exhibited varying degrees of resistance to different antibiotics, in which >80% of isolates showed sensitivity to meropenem, amikacin, and gentamicin. The results indicated that 93.82% of isolates were MDR and 71 out of 76 MDR isolates showed biofilm formation activities. We observed the high prevalence of biofilm-related genes, in which algD+pelF+pslD+ (82.7%) was found to be the prevalent biofilm genotypic pattern. Sixteen isolates (19.75%) possessed class 1 integron (int1) genes. However, statistical analysis revealed no significant association between biofilm formation and multidrug resistance (χ2 = 0.35, P = 0.55). Taken together, hospital wastewater in Dhaka city may act as a reservoir for MDR and biofilm-forming P. aeruginosa, and therefore, the adequate treatment of wastewater is recommended to reduce the occurrence of outbreaks.


Assuntos
Antibacterianos , Biofilmes , Farmacorresistência Bacteriana Múltipla , Hospitais , Pseudomonas aeruginosa , Águas Residuárias , Biofilmes/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/fisiologia , Pseudomonas aeruginosa/isolamento & purificação , Pseudomonas aeruginosa/genética , Águas Residuárias/microbiologia , Bangladesh/epidemiologia , Antibacterianos/farmacologia , Integrons , Testes de Sensibilidade Microbiana
6.
Pak J Pharm Sci ; 37(2(Special)): 429-434, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38822546

RESUMO

Dental implants are commonly used for tooth replacement tools due to their good oral rehabilitation and reconstruction capacities. Dental implants treatment for natural teeth is desired to achieve successful implants treatment with improved osseointegration through promotion of mammalian cell activity and prevention of bacterial activity. Honey is potentially known for its antimicrobial and antibacterial potential, specifically for burns and wound healing. In this study, honey based silver nanoparticles were synthesized using various concentrations of honey. The synthesized HNY-AgNPs, MSN and HNY-AgMSN were characterized for their surface Plasmon resonance using UV spectroscopy, Hydrodynamic diameter using Zetasizer. Morphology using AFM. Furthermore, surface functional groups were characterized using FTIR spectroscopy at 4cm-1 resolutions. The developed hybrid nanoparticles were tested for their anti-bacterial activity at concentration of 3000µg/mL. It was found HNY-AgNPs was active against both bacterial strains i.e, Streptococcus mutans and streptococcus aureus. HNY-AgNPs-MSN hybrid implant demonstrated potential new type of dental implants, which can offer an effective design for the fabrication of advanced dental implants.


Assuntos
Antibacterianos , Implantes Dentários , Mel , Nanopartículas Metálicas , Prata , Streptococcus mutans , Antibacterianos/farmacologia , Antibacterianos/síntese química , Prata/química , Prata/farmacologia , Streptococcus mutans/efeitos dos fármacos , Nanopartículas Metálicas/química , Testes de Sensibilidade Microbiana , Staphylococcus aureus/efeitos dos fármacos , Espectroscopia de Infravermelho com Transformada de Fourier
7.
Food Res Int ; 188: 114408, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38823853

RESUMO

Biopreservation strategies such as the use of Mediterranean plant extracts to ensure food safety are promising to deal with the emergence of antimicrobial resistances and the overreliance on food chemical additives. In the last few decades, antimicrobial susceptibility testing (AST) for evaluating the in vitro antibacterial potential of plant extracts against the most relevant foodborne pathogens has been widely reported in the literature. The current meta-analysis aimed to summarise and analyse the extensive evidence available in the literature regarding the in vitro antimicrobial capability of Allium, Ocimum and Thymus spp. extracts against foodborne pathogens. A systematic review was carried out to gather data on AST results of these extracts against Listeria monocytogenes, Staphylococcus aureus, Salmonella spp., Escherichia coli and Bacillus cereus, including inhibition diameters (ID) and minimum inhibitory concentrations (MIC). A total of 742 records were gathered from a raw collection of 2,065 articles. Weighted mixed-effect linear models were adjusted to data to obtain pooled ID, pooled MIC and the relationship between both model estimations and observations. The pooled results revealed B. cereus as the most susceptible bacteria to Allium sativum (pooled ID = 20.64 ± 0.61 mm) by diffusion methods and S. aureus (pooled MIC = 0.146 mg/mL) by dilution methods. Diffusion methods did not yield conclusive results for Ocimum spp. extracts; however, the lowest pooled MIC was obtained for S. aureus (0.263 mg/mL). Among the foodborne pathogens evaluated, B. cereus showed the highest sensitivity to Thymus spp. extracts by both diffusion and dilution methods (pooled ID = 28.90 ± 2.34 mm and MIC = 0.075 mg/mL). The methodology used for plant extraction was found to not significantly affect MIC values (p > 0.05). Overall, the antimicrobial effectiveness of the studied extracts against Gram-positive and Gram-negative bacteria was demonstrated. Finally, the robustness of the meta-regression model was confirmed, also revealing an inversely proportional correlation between the ID and MIC measurements (p < 0.0001). These results provide a robust scientific basis on the factors affecting the in vitro antimicrobial efficacy of extracts from Mediterranean plants. They also provide valuable information for stakeholders involved in their industrial application in food, including producers, regulatory agencies and consumers which demand green-labelled foods.


Assuntos
Allium , Antibacterianos , Microbiologia de Alimentos , Testes de Sensibilidade Microbiana , Ocimum , Extratos Vegetais , Thymus (Planta) , Thymus (Planta)/química , Extratos Vegetais/farmacologia , Ocimum/química , Allium/química , Antibacterianos/farmacologia , Inocuidade dos Alimentos , Bacillus cereus/efeitos dos fármacos , Bacillus cereus/crescimento & desenvolvimento , Listeria monocytogenes/efeitos dos fármacos , Listeria monocytogenes/crescimento & desenvolvimento
8.
Food Res Int ; 188: 114491, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38823842

RESUMO

Minimum inhibitory concentrations (MIC) assays are often questioned for their representativeness. Especially when foodborne pathogens are tested, it is of crucial importance to also consider parameters of the human digestive system. Hence, the current study aimed to assess the inhibitory capacity of two antibiotics, ciprofloxacin and tetracycline, against Salmonella enterica and Listeria monocytogenes, under representative environmental conditions. More specifically, aspects of the harsh environment of the human gastrointestinal tract (GIT) were gradually added to the experimental conditions starting from simple aerobic lab conditions into an in vitro simulation of the GIT. In this way, the effects of parameters including the anoxic environment, physicochemical conditions of the GIT (low gastric pH, digestive enzymes, bile acids) and the gut microbiota were evaluated. The latter was simulated by including a representative consortium of selected gut bacteria species. In this study, the MIC of the two antibiotics against the relevant foodborne pathogens were established, under the previously mentioned environmental conditions. The results of S. enterica highlighted the importance of the anaerobic environment when conducting such studies, since the pathogen thrived under such conditions. Inclusion of physicochemical barriers led to exactly opposite results for S. enterica and L. monocytogenes since the former became more susceptible to ciprofloxacin while the latter showed lower susceptibility towards tetracycline. Finally, the inclusion of gut bacteria had a bactericidal effect against L. monocytogenes even in the absence of antibiotics, while gut bacteria protected S. enterica from the effect of ciprofloxacin.


Assuntos
Antibacterianos , Ciprofloxacina , Listeria monocytogenes , Testes de Sensibilidade Microbiana , Salmonella enterica , Tetraciclina , Ciprofloxacina/farmacologia , Listeria monocytogenes/efeitos dos fármacos , Salmonella enterica/efeitos dos fármacos , Tetraciclina/farmacologia , Antibacterianos/farmacologia , Humanos , Trato Gastrointestinal/microbiologia , Microbioma Gastrointestinal/efeitos dos fármacos , Microbiologia de Alimentos , Concentração de Íons de Hidrogênio , Doenças Transmitidas por Alimentos/microbiologia , Doenças Transmitidas por Alimentos/prevenção & controle
9.
Carbohydr Polym ; 339: 122209, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38823899

RESUMO

The escalating global health concern arises from chronic wounds induced by bacterial infections, posing a significant threat to individuals. Consequently, an imperative exist for the development of hydrogel dressings to facilitate prompt wound monitoring and efficacious wound management. To this end, pH-sensitive bromothymol blue (BTB) and pH-responsive drug tetracycline hydrochloride (TH) were introduced into the polysaccharide-based hydrogel to realize the integration of wound monitoring and controlled treatment. Polysaccharide-based hydrogels were formed via a Schiff base reaction by cross-linking carboxymethyl chitosan (CMCS) on an oxidized sodium alginate (OSA) skeleton. BTB was used as a pH indicator to monitor wound infection through visual color changes visually. TH could be dynamically released through the pH response of the Schiff base bond to provide effective treatment and long-term antibacterial activity for chronically infected wounds. In addition, introducing polylactic acid nanofibers (PLA) enhanced the mechanical properties of hydrogels. The multifunctional hydrogel has excellent mechanical, self-healing, injectable, antibacterial properties and biocompatibility. Furthermore, the multifaceted hydrogel dressing under consideration exhibits noteworthy capabilities in fostering the healing process of chronically infected wounds. Consequently, the research contributes novel perspectives towards the advancement of intelligent and expeditious bacterial infection monitoring and dynamic treatment platforms.


Assuntos
Alginatos , Antibacterianos , Bandagens , Quitosana , Hidrogéis , Nanofibras , Cicatrização , Nanofibras/química , Hidrogéis/química , Hidrogéis/farmacologia , Cicatrização/efeitos dos fármacos , Antibacterianos/química , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Concentração de Íons de Hidrogênio , Quitosana/química , Quitosana/análogos & derivados , Quitosana/farmacologia , Alginatos/química , Animais , Staphylococcus aureus/efeitos dos fármacos , Tetraciclina/química , Tetraciclina/farmacologia , Camundongos , Infecção dos Ferimentos/tratamento farmacológico , Polissacarídeos/química , Escherichia coli/efeitos dos fármacos , Bases de Schiff/química , Testes de Sensibilidade Microbiana , Humanos
10.
Carbohydr Polym ; 339: 122238, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38823908

RESUMO

The study aimed to develop a novel, transparent and non-toxic coating with antimicrobial, antioxidant, and antifogging properties. The p-coumaric acid-grafted chitosan (CS-PCA) was synthesized via a carbodiimide coupling reaction and then characterized. The CS-PCA coatings were further prepared using the casting method. The CS-PCA coatings obtained exhibited excellent transparency, UV-light barrier ability, and antifogging properties, as confirmed by spectroscopy and antifogging tests. The CS-PCA coatings showed stronger antioxidant capacity and antimicrobial properties against Escherichia coli, Staphylococcus aureus and Botrytis cinerea compared to CS. The multifunctional coatings were further coated on the polyethylene cling film and their effectiveness was confirmed through a strawberry preservation test. The decay of the strawberries was reduced by CS-PCA coated film at room temperature.


Assuntos
Antioxidantes , Quitosana , Ácidos Cumáricos , Escherichia coli , Embalagem de Alimentos , Fragaria , Frutas , Propionatos , Staphylococcus aureus , Quitosana/química , Quitosana/farmacologia , Ácidos Cumáricos/química , Ácidos Cumáricos/farmacologia , Antioxidantes/farmacologia , Antioxidantes/química , Escherichia coli/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Fragaria/microbiologia , Embalagem de Alimentos/métodos , Frutas/química , Propionatos/química , Propionatos/farmacologia , Botrytis/efeitos dos fármacos , Anti-Infecciosos/farmacologia , Anti-Infecciosos/química , Antibacterianos/farmacologia , Antibacterianos/química , Testes de Sensibilidade Microbiana
11.
Microb Cell Fact ; 23(1): 161, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38822407

RESUMO

Multi resistant fungi are on the rise, and our arsenal compounds are limited to few choices in the market such as polyenes, pyrimidine analogs, azoles, allylamines, and echinocandins. Although each of these drugs featured a unique mechanism, antifungal resistant strains did emerge and continued to arise against them worldwide. Moreover, the genetic variation between fungi and their host humans is small, which leads to significant challenges in new antifungal drug discovery. Endophytes are still an underexplored source of bioactive secondary metabolites. Many studies were conducted to isolate and screen endophytic pure compounds with efficacy against resistant yeasts and fungi; especially, Candida albicans, C. auris, Cryptococcus neoformans and Aspergillus fumigatus, which encouraged writing this review to critically analyze the chemical nature, potency, and fungal source of the isolated endophytic compounds as well as their novelty features and SAR when possible. Herein, we report a comprehensive list of around 320 assayed antifungal compounds against Candida albicans, C. auris, Cryptococcus neoformans and Aspergillus fumigatus in the period 1980-2024, the majority of which were isolated from fungi of orders Eurotiales and Hypocreales associated with terrestrial plants, probably due to the ease of laboratory cultivation of these strains. 46% of the reviewed compounds were active against C. albicans, 23% against C. neoformans, 29% against A. fumigatus and only 2% against C. auris. Coculturing was proved to be an effective technique to induce cryptic metabolites absent in other axenic cultures or host extract cultures, with Irperide as the most promising compounds MIC value 1 µg/mL. C. auris was susceptible to only persephacin and rubiginosin C. The latter showed potent inhibition against this recalcitrant strain in a non-fungicide way, which unveils the potential of fungal biofilm inhibition. Further development of culturing techniques and activation of silent metabolic pathways would be favorable to inspire the search for novel bioactive antifungals.


Assuntos
Antifúngicos , Endófitos , Antifúngicos/farmacologia , Endófitos/metabolismo , Humanos , Testes de Sensibilidade Microbiana , Cryptococcus neoformans/efeitos dos fármacos , Cryptococcus neoformans/metabolismo , Fungos/efeitos dos fármacos , Fungos/metabolismo , Aspergillus fumigatus/efeitos dos fármacos , Aspergillus fumigatus/metabolismo , Candida albicans/efeitos dos fármacos
12.
PLoS One ; 19(6): e0304130, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38861531

RESUMO

Whole Genome Sequencing (WGS) is a promising tool in the global fight against tuberculosis (TB). The aim of this study was to evaluate the use of WGS in routine conditions for detection of drug resistance markers and transmission clusters in a multidrug-resistant TB hot-spot area in Peru. For this, 140 drug-resistant Mycobacterium tuberculosis strains from Lima and Callao were prospectively selected and processed through routine (GenoType MTBDRsl and BACTEC MGIT) and WGS workflows, simultaneously. Resistance was determined in accordance with the World Health Organization mutation catalogue. Agreements between WGS and BACTEC results were calculated for rifampicin, isoniazid, pyrazinamide, moxifloxacin, levofloxacin, amikacin and capreomycin. Transmission clusters were determined using different cut-off values of Single Nucleotide Polymorphism differences. 100% (140/140) of strains had valid WGS results for 13 anti-TB drugs. However, the availability of final, definitive phenotypic BACTEC MGIT results varied by drug with 10-17% of invalid results for the seven compared drugs. The median time to obtain results of WGS for the complete set of drugs was 11.5 days, compared to 28.6-52.6 days for the routine workflow. Overall categorical agreement by WGS and BACTEC MGIT for the compared drugs was 96.5%. Kappa index was good (0.65≤k≤1.00), except for moxifloxacin, but the sensitivity and specificity values were high for all cases. 97.9% (137/140) of strains were characterized with only one sublineage (134 belonging to "lineage 4" and 3 to "lineage 2"), and 2.1% (3/140) were mixed strains presenting two different sublineages. Clustering rates of 3.6% (5/140), 17.9% (25/140) and 22.1% (31/140) were obtained for 5, 10 and 12 SNP cut-off values, respectively. In conclusion, routine WGS has a high diagnostic accuracy to detect resistance against key current anti-TB drugs, allowing results to be obtained through a single analysis and helping to cut quickly the chain of transmission of drug-resistant TB in Peru.


Assuntos
Antituberculosos , Mycobacterium tuberculosis , Tuberculose Resistente a Múltiplos Medicamentos , Sequenciamento Completo do Genoma , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/isolamento & purificação , Peru/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/microbiologia , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Sequenciamento Completo do Genoma/métodos , Humanos , Antituberculosos/farmacologia , Antituberculosos/uso terapêutico , Polimorfismo de Nucleotídeo Único , Farmacorresistência Bacteriana Múltipla/genética , Testes de Sensibilidade Microbiana , Genoma Bacteriano , Masculino , Feminino
13.
Sci Rep ; 14(1): 13235, 2024 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-38853154

RESUMO

The study investigated the economic concerns associated with livestock-associated methicillin-resistant Staphylococcus aureus (LA-MRSA) in livestock (cow), examining its connection to severe infections, antimicrobial resistance (AMR), and virulence factors. The research, conducted in Edo State, Nigeria, analyzed 400 samples (200 rectal and 200 nasal swabs) collected between March 2018 and February 2019. MRSA prevalence was identified using conventional culture-based methods and polymerase chain reaction (PCR) techniques, revealing 63.5% (n = 254) for Staphylococcus aureus and 55% (n = 220) for MRSA. Of the 76 mecA-positive MRSA isolates, 64.5% (n = 49) exhibited multidrug resistance (MDR) while the remaining were sensitive to specific antimicrobials. Key virulence genes, such as PVL (81.6%; n = 62) and tsst-1 (44.7%; n = 34), were prevalent, along with AMR genes like mecC, tetM, ermA, ermC, vanA, and vanC. Staphylococcal chromosomal cassette mec (SCCmec) typing identified different types, notably II, IVa, and IVb. Biofilm formation, a crucial virulence factor varied in strength, is associated with icaA and icaB genes (p < 0.01). The findings highlighted substantial AMR and biofilm-forming capacity within LA-MRSA isolates, emphasizing the importance of ongoing surveillance for informed treatment strategies, AMR policies, and control measures against MDR staphylococcal infections.


Assuntos
Biofilmes , Gado , Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Fatores de Virulência , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Animais , Fatores de Virulência/genética , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/veterinária , Gado/microbiologia , Bovinos , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla/genética , Nigéria/epidemiologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo
14.
AAPS J ; 26(4): 67, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38862870

RESUMO

Addressing the intertwined challenges of antimicrobial resistance and impaired wound healing in diabetic patients, an oil/water emulsion-based nano-ointment integrating phenylpropanoids-Eugenol and Cinnamaldehyde-with positively-charged silver nanoparticles was synthesized. The process began with the synthesis and characterization of nano-silver, aimed at ensuring the effectiveness and safety of the nanoparticles in biological applications. Subsequent experiments determined the minimum inhibitory concentration (MIC) against pathogens such as Streptococcus aureus, Pseudomonas aeruginosa and Candida albicans. These MIC values of all three active leads guided the strategic formulation of an ointment base, which effectively integrated the bioactive components. Evaluations of this nano-ointment revealed enhanced antimicrobial activity against both clinical and reference bacterial strains and it maintained stability after freeze-thaw cycles. Furthermore, the ointment demonstrated superior in-vitro diabetic wound healing capabilities and significantly promoted angiogenesis, as shown by enhanced blood vessel formation in the Chorioallantoic Membrane assay. These findings underscore the formulation's therapeutic potential, marking a significant advance in the use of nanotechnology for topical wound care.


Assuntos
Nanopartículas Metálicas , Testes de Sensibilidade Microbiana , Pomadas , Prata , Cicatrização , Prata/administração & dosagem , Prata/química , Prata/farmacologia , Cicatrização/efeitos dos fármacos , Nanopartículas Metálicas/química , Nanopartículas Metálicas/administração & dosagem , Animais , Acroleína/análogos & derivados , Acroleína/administração & dosagem , Acroleína/farmacologia , Acroleína/química , Candida albicans/efeitos dos fármacos , Anti-Infecciosos/administração & dosagem , Anti-Infecciosos/farmacologia , Pseudomonas aeruginosa/efeitos dos fármacos , Administração Tópica , Humanos , Antibacterianos/administração & dosagem , Antibacterianos/farmacologia , Staphylococcus aureus/efeitos dos fármacos
15.
P R Health Sci J ; 43(2): 68-72, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38860959

RESUMO

OBJECTIVE: Monitoring the susceptibility patterns of Neisseria gonorrhoeae is essential for the continuing compliance with current treatment recommendations. Puerto Rico conducts susceptibility tests on N. gonorrhoeae; however, trends on antimicrobial resistance in the island have not been reported since the mid 80's. METHODS: We performed a secondary analysis of a national data repository on the antimicrobial susceptibility of N. gonorrhoeae isolates between 2012 and 2017; a period of time when the CDC recommended a single dose of ceftriaxone and azithromycin for the treatment of uncomplicated gonorrhea. Data on susceptibility to eight antibiotics using the standard disk diffusion method was obtained for 30.0% (84/276) of the samples collected from the Sexually Transmitted Disease clinics in Puerto Rico. We also performed patient demographic analyses linked to resistance. RESULTS: Rates of resistance to ceftriaxone and azithromycin were 0% and 4.0% (2/50), respectively. The percentage of isolates resistant to antimicrobials no longer recommended in Puerto Rico, such as tetracycline, ciprofloxacin, and penicillin, was 86.0% (43/50), 76.0% (38/50), and 38.0% (19/50), respectively. Prevalence of resistant N. gonorrhoeae was higher among men who have sex with men, MSM (79%, 37/47). DISCUSSION: Lack of resistance to ceftriaxone and slow emergence of azithromycin resistance was identified from 2012-2017. It is imperative to continue the surveillance for emerging patterns of resistance, especially for ceftriaxone, as it is part of the current treatment guidelines. Therefore, protocols for culture based surveillance, including sample transport and processing, should be strengthened to ensure quality assured epidemiology of gonococcal resistance in Puerto Rico.


Assuntos
Antibacterianos , Farmacorresistência Bacteriana , Gonorreia , Testes de Sensibilidade Microbiana , Neisseria gonorrhoeae , Porto Rico , Neisseria gonorrhoeae/efeitos dos fármacos , Neisseria gonorrhoeae/isolamento & purificação , Humanos , Masculino , Gonorreia/tratamento farmacológico , Gonorreia/microbiologia , Gonorreia/epidemiologia , Feminino , Antibacterianos/farmacologia , Antibacterianos/administração & dosagem , Adulto , Adulto Jovem , Azitromicina/farmacologia , Azitromicina/administração & dosagem , Ceftriaxona/farmacologia , Adolescente , Pessoa de Meia-Idade
16.
P R Health Sci J ; 43(2): 73-78, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38860960

RESUMO

OBJECTIVE: Increased mupirocin use leads to mupirocin resistance and is associated with persistence of methicillin-resistant Staphylococcus aureus (MRSA) carriers, prolonged hospitalization, and significant economic burdens for health systems. The study aimed to investigate the antimicrobial activity of compounds of Salvia rosmarinus L. ("rosemary", formerly Rosmarinus officinalis), alone or in combination with mupirocin, against multidrug resistant MRSA using isolates obtained from pediatric patients. METHODS: The in vitro antibacterial activity of the monoterpene α-pinene (α-Pi), a rosemary essential oil constituent, alone and in combination with mupirocin, was evaluated by determining the minimum inhibitory concentrations and minimum bactericidal concentrations (MBCs) and the fractional inhibitory concentration indices (FICIs) and fractional bactericidal concentration indices against multidrug-resistant clinical MRSA strains. The in vivo efficacy of α-Pi, alone and in combination with mupirocin, to eradicate MRSA infection was determined using an optimized mouse model of MRSA-infected wounds. Mouse skin samples (obtained via biopsy) were assessed for toxicity, and rabbit skin samples for irritation. RESULTS: Both in vitro and in vivo, α-Pi was active against MRSA strains and acted synergistically with mupirocin against MRSA strains. Mupirocin-monoterpene combinations exhibited FICI values of 0.2 to 0.4, reducing the MBC of topical mupirocin 33-fold. A topical formulation containing α-Pi and mupirocin enhanced the efficacy of mupirocin in an in vivo MRSA-infected mouse skin model without significantly harming the skin of mice and rabbits. CONCLUSIONS: A topical formulation combining mupirocin and α-Pi may aid in the development of innovative agents for treating MRSA infections.


Assuntos
Antibacterianos , Monoterpenos Bicíclicos , Farmacorresistência Bacteriana Múltipla , Sinergismo Farmacológico , Quimioterapia Combinada , Staphylococcus aureus Resistente à Meticilina , Testes de Sensibilidade Microbiana , Mupirocina , Mupirocina/administração & dosagem , Mupirocina/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Animais , Camundongos , Antibacterianos/administração & dosagem , Antibacterianos/farmacologia , Monoterpenos Bicíclicos/administração & dosagem , Monoterpenos Bicíclicos/farmacologia , Humanos , Monoterpenos/farmacologia , Monoterpenos/administração & dosagem , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/microbiologia , Modelos Animais de Doenças , Feminino
17.
Arch Microbiol ; 206(7): 298, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38860999

RESUMO

A decreased chloramphenicol susceptibility in Haemophilus influenzae is commonly caused by the activity of chloramphenicol acetyltransferases (CATs). However, the involvement of membrane proteins in chloramphenicol susceptibility in H. influenzae remains unclear. In this study, chloramphenicol susceptibility testing, whole-genome sequencing, and analyses of membrane-related genes were performed in 51 H. influenzae isolates. Functional complementation assays and structure-based protein analyses were conducted to assess the effect of proteins with sequence substitutions on the minimum inhibitory concentration (MIC) of chloramphenicol in CAT-negative H. influenzae isolates. Six isolates were resistant to chloramphenicol and positive for type A-2 CATs. Of these isolates, A3256 had a similar level of CAT activity but a higher chloramphenicol MIC relative to the other resistant isolates; it also had 163 specific variations in 58 membrane genes. Regarding the CAT-negative isolates, logistic regression and receiver operator characteristic curve analyses revealed that 48T > G (Asn16Lys), 85 C > T (Leu29Phe), and 88 C > A (Leu30Ile) in HI_0898 (emrA), and 86T > G (Phe29Cys) and 141T > A (Ser47Arg) in HI_1177 (artM) were associated with enhanced chloramphenicol susceptibility, whereas 997G > A (Val333Ile) in HI_1612 (hmrM) was associated with reduced chloramphenicol susceptibility. Furthermore, the chloramphenicol MIC was lower in the CAT-negative isolates with EmrA-Leu29Phe/Leu30Ile or ArtM-Ser47Arg substitution and higher in those with HmrM-Val333Ile substitution, relative to their counterparts. The Val333Ile substitution was associated with enhanced HmrM protein stability and flexibility and increased chloramphenicol MICs in CAT-negative H. influenzae isolates. In conclusion, the substitution in H. influenzae multidrug efflux pump HmrM associated with reduced chloramphenicol susceptibility was characterised.


Assuntos
Substituição de Aminoácidos , Antibacterianos , Proteínas de Bactérias , Cloranfenicol O-Acetiltransferase , Cloranfenicol , Haemophilus influenzae , Testes de Sensibilidade Microbiana , Cloranfenicol/farmacologia , Haemophilus influenzae/genética , Haemophilus influenzae/efeitos dos fármacos , Haemophilus influenzae/metabolismo , Haemophilus influenzae/isolamento & purificação , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Cloranfenicol O-Acetiltransferase/genética , Cloranfenicol O-Acetiltransferase/metabolismo , Farmacorresistência Bacteriana Múltipla/genética , Proteínas de Membrana Transportadoras/genética , Proteínas de Membrana Transportadoras/metabolismo , Resistência ao Cloranfenicol/genética , Humanos , Infecções por Haemophilus/microbiologia , Sequenciamento Completo do Genoma
18.
PLoS One ; 19(6): e0304599, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38829840

RESUMO

Extended-spectrum beta-lactamase (ESBL) Escherichia coli (E. coli) is an emerging pathogen of high concern given its resistance to extended-spectrum cephalosporins. Broiler chicken, which is the number one consumed meat in the United States and worldwide, can be a reservoir of ESBL E. coli. Backyard poultry ownership is on the rise in the United States, yet there is little research investigating prevalence of ESBL E. coli in this setting. This study aims to identify the prevalence and antimicrobial resistance profiles (phenotypically and genotypically) of ESBL E. coli in some backyard and commercial broiler farms in the U.S. For this study ten backyard and ten commercial farms were visited at three time-points across flock production. Fecal (n = 10), litter/compost (n = 5), soil (n = 5), and swabs of feeders and waterers (n = 6) were collected at each visit and processed for E. coli. Assessment of ESBL phenotype was determined through using disk diffusion with 3rd generation cephalosporins, cefotaxime and ceftazidime, and that with clavulanic acid. Broth microdilution and whole genome sequencing were used to investigate both phenotypic and genotypic resistance profiles, respectively. ESBL E. coli was more prevalent in backyard farms with 12.95% of samples testing positive whereas 0.77% of commercial farm samples were positive. All isolates contained a blaCTX-M gene, the dominant variant being blaCTX-M-1, and its presence was entirely due to plasmids. Our study confirms concerns of growing resistance to fourth generation cephalosporin, cefepime, as roughly half (51.4%) of all isolates were found to be susceptible dose-dependent and few were resistant. Resistance to non-beta lactams, gentamicin and ciprofloxacin, was also detected in our samples. Our study identifies prevalence of blaCTX-M type ESBL E. coli in U.S. backyard broiler farms, emphasizing the need for interventions for food and production safety.


Assuntos
Antibacterianos , Galinhas , Infecções por Escherichia coli , Escherichia coli , Plasmídeos , beta-Lactamases , Animais , beta-Lactamases/genética , Escherichia coli/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/isolamento & purificação , Galinhas/microbiologia , Estados Unidos/epidemiologia , Plasmídeos/genética , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/microbiologia , Infecções por Escherichia coli/veterinária , Prevalência , Antibacterianos/farmacologia , Doenças das Aves Domésticas/microbiologia , Doenças das Aves Domésticas/epidemiologia , Testes de Sensibilidade Microbiana , Fezes/microbiologia , Proteínas de Escherichia coli/genética , Fazendas
19.
PLoS One ; 19(6): e0302440, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38870165

RESUMO

Rhizoctonia solani, the causative agent of sheath blight disease in rice, poses a significant threat to agricultural productivity. Traditional management approaches involving chemical fungicides have been effective but come with detrimental consequences for the ecosystem. This study aimed to investigate sustainable alternatives in the form of antifungal peptides derived from Solanaceous plant species as potential agents against R. solani. Peptide extracts were obtained using an optimized antimicrobial peptide (AMP) extraction method and desalted using the solid-phase extraction technique. The antifungal potential of peptide-rich extracts from Solanum tuberosum and Capsicum annum was assessed through in vitro tests employing the agar well diffusion method. Furthermore, peptide-protein docking analysis was performed on HPEPDOCK and HDOCK server; and molecular dynamics simulations (MDS) of 100 ns period were performed using the Gromacs 2020.4. The results demonstrated significant inhibition zones for both extracts at concentrations of 100 mg/mL. Additionally, the extracts of Solanum tuberosum and Capsicum annum had minimum inhibitory concentrations of 50 mg/mL and 25 mg/mL, respectively with minimum fungicidal concentrations of 25 mg/mL. Insights into the potential mechanisms of key peptides inhibiting R. solani targets were gleaned from in-silico studies. Notably, certain AMPs exhibited favorable free energy of binding against pathogenicity-related targets, including histone demethylase, sortin nexin, and squalene synthase, in protein-peptide docking simulations. Extended molecular dynamics simulations lasting 100 ns and MM-PBSA calculations were performed on select protein-peptide complexes. AMP10 displayed the most favorable binding free energy against all target proteins, with AMP3, AMP12b, AMP6, and AMP15 also exhibiting promising results against specific targets of R. solani. These findings underscore the potential of peptide extracts from S. tuberosum and C. annum as effective antifungal agents against rice sheath blight caused by R. solani.


Assuntos
Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Oryza , Doenças das Plantas , Rhizoctonia , Oryza/microbiologia , Doenças das Plantas/microbiologia , Rhizoctonia/efeitos dos fármacos , Peptídeos Antimicrobianos/farmacologia , Peptídeos Antimicrobianos/química , Antifúngicos/farmacologia , Antifúngicos/química , Antifúngicos/isolamento & purificação , Solanum tuberosum/microbiologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Solanaceae/química , Testes de Sensibilidade Microbiana , Simulação por Computador , Capsicum/microbiologia , Capsicum/química
20.
Nat Commun ; 15(1): 5074, 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38871710

RESUMO

Antimicrobial resistance (AMR) is a growing public health crisis that requires innovative solutions. Current susceptibility testing approaches limit our ability to rapidly distinguish between antimicrobial-susceptible and -resistant organisms. Salmonella Typhimurium (S. Typhimurium) is an enteric pathogen responsible for severe gastrointestinal illness and invasive disease. Despite widespread resistance, ciprofloxacin remains a common treatment for Salmonella infections, particularly in lower-resource settings, where the drug is given empirically. Here, we exploit high-content imaging to generate deep phenotyping of S. Typhimurium isolates longitudinally exposed to increasing concentrations of ciprofloxacin. We apply machine learning algorithms to the imaging data and demonstrate that individual isolates display distinct growth and morphological characteristics that cluster by time point and susceptibility to ciprofloxacin, which occur independently of ciprofloxacin exposure. Using a further set of S. Typhimurium clinical isolates, we find that machine learning classifiers can accurately predict ciprofloxacin susceptibility without exposure to it or any prior knowledge of resistance phenotype. These results demonstrate the principle of using high-content imaging with machine learning algorithms to predict drug susceptibility of clinical bacterial isolates. This technique may be an important tool in understanding the morphological impact of antimicrobials on the bacterial cell to identify drugs with new modes of action.


Assuntos
Antibacterianos , Ciprofloxacina , Farmacorresistência Bacteriana , Aprendizado de Máquina , Testes de Sensibilidade Microbiana , Salmonella typhimurium , Ciprofloxacina/farmacologia , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/isolamento & purificação , Antibacterianos/farmacologia , Humanos , Infecções por Salmonella/microbiologia , Infecções por Salmonella/tratamento farmacológico , Algoritmos
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